Spindle or worm drive for adjustment devices in motor vehicles

ABSTRACT

A spindle or worm drive for adjustment devices in motor vehicles. The device is secured with a fixed spindle or a fixed toothed rack to the first of two parts which can be adjusted in relation to each other, and is provided with a gear mechanism which is connected to the second of the two parts which can be adjusted in relation to each other. The gear housing is free from backlash and is enclosed by at least one bearing shell such that it is pivotable about at least one axis. The bearing shell consisting of two bearing plates which fit into one another and which can be joined to each other after enclosure of the gear housing. The gear housing is made of plastic and is provided with a concave or convex housing part which is surrounded by a convex or concave bearing shell section made of a material which is suitable for receiving crash forces, especially a metal material.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a National Phase Patent Application of InternationalApplication Number PCT/DE2002/04282, filed on Nov. 18, 2002, whichclaims priority of German Patent Application Number 102 06 524.1, filedon Feb. 13, 2002, and German Patent Application Number 102 50 994.8,filed on Oct. 30, 2002.

BACKGROUND

The invention relates to a spindle or worm drive for adjustment devicesin motor vehicles, more particularly for seat adjustment devices, windowlifters and sliding roofs.

From DE 198 61 100 A1 a spindle drive is known for adjustment devices inmotor vehicles having a fixed spindle which is fixed on a first of tworelatively rotatable parts, a gearing mechanism which is mounted on thesecond of the relatively rotatable parts, and a gear housing foraccommodating the gearing. The gear housing consists of two housingplates which are fixed against each other by means of push-fitconnections and which are designed as supporting connecting points wherethe housing plates are held together and which take up the gear forces.The push-fit connections have raised zones and recesses which fit intoeach other and initially form a play-fit. The housing plates are fixedby plastically deforming the material in the region of the push-fitconnections.

From U.S. Pat. No. 4,802,374 a spindle drive is known for a seatlongitudinal adjuster in motor vehicles which contains a spindle whichis connected to the adjusting rail of the seat longitudinal adjuster andwhich can be driven through an electric motor by a spindle nut, wormwheel and a worm connected to a motor shaft. The worm, the worm wheeland the spindle nut are mounted in a retaining clip having twocylindrical sleeves which intersect at right angles. A retaining flangewhich is connected to the base rail of the seat longitudinal adjusterand consists of a clip with a rectangular window-shaped openingsurrounds the cylindrical sleeves of the retaining clip through theframe of the window-shaped opening, and thus secures the position of theretaining clip.

With this spindle drive which is known from U.S. Pat. No. 4,802,374 thetolerances of the individual component parts determine the overall playof the spindle drive so that to reduce the clearance of the spindledrive narrow tolerances have to be set which requires considerablemanufacturing expense.

A further drawback of the known spindle drives is that the retainingflange does indeed secure the position of the retaining clip but offersno security in the event of a crash since the retaining flange onlysurrounds a part of the retaining clip and in the event of a crash isbent so that the coupling between the movable adjusting rail and thebase rail fixed on the body is released and thus a vehicle seatconnected to the adjusting rail will move uncontrollably.

The object of the present invention is therefore to provide a spindle orworm drive for adjustment devices in motor vehicles of the type alreadydescribed which guarantees a play-free bearing of the gear elementsprotected against dirt, a crash-safe connection of the gearing mechanismand thus of the adjustment device as well as a bearing of the gearingmechanism which is able to pivot when necessary about at least one axis.

BRIEF DESCRIPTION

The solution according to the invention provides a play-free bearing ofthe gearing elements protected against dirt as well as a crash-safesupport of the gearing mechanism and thus of the relatively movableparts of the adjustment device as well as a pivotal action of thegearing mechanism for connecting adjustment parts which are able topivot about an axis.

The solution according to the invention is based on the idea ofarranging the gear elements in a gear housing surrounding the gearelements in the form of a capsule protected against dirt and damage andof arranging the gear housing in turn free from backlash and wherenecessary able to pivot about at least one axis in a bearing shell whichis designed and intended to take up the crash forces and thus to ensurea crash-safe support of the gear mechanism so that the relativelymovable parts of the adjustment device also remain connected togethereven in the event of a crash.

The gearing housing preferably consists of plastics while the bearingshell is made from a material, more particularly a metal material, whichis suitable for absorbing crash forces. This enables on the one hand asimple manufacture of the gear housing, particularly in an injectioncasting process with high accuracy in fitting while the crash forces aretaken up by the bearing shell which is made of metal so that the gearhousing itself does not have to be dimensioned to take up the crashforces since these are distributed over a wide surface area over thegear housing through the bearing shell.

The ability of the gear housing to pivot about an axis, for exampleabout a pivotal axis running perpendicular to the spindle or toothedrack is preferably achieved through a concave or convex housing part ofthe gear housing and a convex or concave bearing shell section whichsurrounds the concave or convex housing part.

In an exemplary embodiment of the drive the bearing shell is made in twoparts; namely the bearing shell consists of two bearing plates which canbe fitted into each other and which can be connected together after thegear housing has been fitted and which can be fixed on the second of thetwo parts which are adjustable relative to each other.

Making the bearing shell from two bearing plates which can be fittedinto each other means that it is easy to fit the bearing shell free frombacklash on the gear housing since the bearing plates can be placedaround the gear housing, pushed together to zero tolerance and thenconnected together in this position, for example, by laser welding.

The preferably U-shaped bearing plates can be fitted together engagingin each other by means of the side arms in the direction of thelongitudinal extension of the spindle or toothed rack whereby theconnecting arms between the side arms have through openings for passingthrough the spindle or toothed rack, adjoined on each side by theconcave or convex bearing shell sections which correspond with theconvex or concave housing parts of the gear housing.

This design combines the rotational movement of the gear mechanisminside the bearing shell formed by the bearing plates with aclearance-free connection between the gear housing and the bearing shellwith integrated guide of the spindle or toothed rack.

The side arms of the one bearing plate are preferably formed as tabswhich engage in the other bearing plate in the one side arm providedwith a window-shaped opening and the other side arm provided with aU-shaped recess. To compensate for tolerances, the tab-shaped side armof the one bearing plate is longer in the connecting direction of thebearing plates than the window-shaped opening of the other bearingplate, and the tab-shaped side arm of the one bearing plate is shorterthan the U-shaped recess of the side arm of the other bearing platewhereby the tab-shaped side arm of the one bearing plate can be fittedin the connecting direction of the bearing plates through a cut-outsection in the connecting arm of the other bearing plate which widensout the window-shaped opening of the corresponding side arm of the otherbearing plate.

Since the tab-shaped side arm of the one bearing plate in the connectingdirection of the bearing plates is longer than the window shaped openingand the frame surrounding the window shaped opening is longer than thetab shaped side arm, the fixing points provided at the front ends of thetab shaped side arm in the connecting direction, and the framesurrounding the window-shaped opening are freely accessible forattaching the spindle or worm gearing on one of the two parts which aremovable relative to each other.

In order to connect the bearing plates while guaranteeing a play-freecoupling with the gear housing the side arms of the bearing plates arepositively connected together in the assembled state of the adjustmentdevice, more particularly through welding contours.

In a further exemplary embodiment of the drive the bearing shell isdesigned in four parts and consists of four bearing plates; wherebasically the bearing shell has a base plate, two side plates and a topplate, wherein the base plate and the top plate run substantiallyparallel to each other and are held spaced apart yet connected togetherthrough the two side plates which are mounted substantially parallel toeach other. With this further special embodiment there is the importantadvantage that the manufacturing tolerances can be compensatedparticularly easily since the relative position of the four bearingplates (bearing shell plates) relative to each other can be re-alignedvery simply. Thus the freedom from backlash between the gear housing andbearing shell can be adjusted and permanently fixed in a very simplemanner.

In the further exemplary embodiment, the base plate optionally has twoslot like openings of which one serves to hold a fixing tab of one ofthe two side plates and the other opening serves to hold the fixing tabof the other of the two side plates.

The one side plate can thereby advantageously have a further fixing tabwhich is mounted on a side of the side plate opposite the one fixing taband engages in a recess in the edge of the top plate.

Through openings are advantageously provided in each of the side platesfor passing through the spindle or toothed rack.

In order to fix the freedom from backlash between the gear housing andthe bearing shell in a particularly secure manner it is regarded asadvantageous if the side plates and the gear housing lie close againsteach other over a wide surface area. This can advantageously be achievedif the side plates have concave and convex bearing shell sections withwhich the gear housing is fixed.

The through openings in the side plates as well as the concave or convexbearing shell sections can thereby be arranged relative to each other sothat the concave and convex bearing shell sections are arranged on eachside of the through openings for passing through the spindle or toothedrack.

After the base plate, the two side plates and the top plate have beenaligned relative to each other and the freedom from backlash between thegear housing and bearing shell is ensured, the base plate, the two sideplates and the top plate can be welded together for fixing. Inparticular, laser welding is regarded as advantageous for fixingpurposes. The welded seams for connecting the bearing plates shouldthereby lie in grooves which are formed in the connecting regionsbetween the bearing plates which stand on one another.

An advantageous method for manufacturing the spindle and/or worm driveaccording to the invention includes the gearing elements after theirconnection with the spindle or toothed rack being inserted into ahousing shell of the gear housing and being connected to a drive elementof the motor shaft so that a gearing cover is connected to the housingshell of the gear housing to close up the gear mechanism and thefinished made gear housing being enclosed free from backlash by abearing shell.

In the case of a two part drive this can advantageously be fitted sothat the bearing plates are pushed from both sides through thefull-length openings onto the spindle, so that the side arms of thebearing plates are pushed into each other until the concave or convexbearing shell sections of the bearing plates adjoin without play againstthe concave and convex housing parts of the gear housing, and so thatthe abutting side edges of the side arms of the bearing plates areconnected together by laser welding, at least over a part of theirlength.

The one end of the spindle can then be connected to a connecting tabwhich is fixed on the first of the two relatively rotatable parts andthe interconnecting bearing plates can be connected to the second of therelatively rotatable parts.

In the case of a four-part bearing shell, it is regarded as advantageousif this is formed from four bearing plates in that two side plates areset up on a base plate, the gear housing is inserted between the twoside plates, a top plate is fitted onto the two side plates and the fourbearing plates are aligned without play relative to each other and thenfixed together.

The two side plates can advantageously be fitted from both sides throughwindow-shaped full-length openings onto the spindle and then aligneduntil the concave and convex bearing shell sections of the side platesbear without play against the concave and convex housing parts of thegear housing.

Fixing the four bearing plates can advantageously be carried out bywelding, more particularly laser welding. In order to avoid “throughwelding” when laser welding, the join should be “butt” welded, thuswelded at an obtuse angle. Laser welding should thereby be carried outin the grooved areas or in the grooves which are formed in theconnecting region of the adjoining bearing plates. It is recommended inthis connection if the laser welding is carried out at an angle of about45° to the bearing plates which are to be connected.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in further detail with reference tothe embodiment illustrated in the drawings.

FIG. 1 is a front exploded view of a first exemplary embodiment of aspindle or worm drive with a two part bearing shell.

FIG. 2 is top exploded view of the device of FIG. 1.

FIG. 3 is bottom exploded view of the device of FIG. 1.

FIG. 4 is front left perspective view of the device of FIG. 1 in itsassembled state.

FIG. 5 is front right perspective view of the device of FIG. 1 in itsassembled state.

FIG. 6 is front perspective view of the device of FIG. 1 in itsassembled state.

FIGS. 7-9 are front perspective views of three of four base plates usedto form bearing shell with four bearing plates for a second exemplaryembodiment of a spindle or worm drive with a four part bearing shell.

FIGS. 10-11 are front perspective views showing how a spindle or wormdrive is connected with the bearings plates shown in FIG. 9.

FIG. 12 is a front perspective view of a top plate.

FIG. 13 is a front perspective view showing the finished assembled drivewith the top plate of FIG. 12 attached to the bearing plates of FIG.7-9.

FIG. 14 is top perspective view showing the finished assembled drive ofFIG. 13.

FIG. 15 is a detail showing how the four bear plates of FIGS. 13 and 14are connected and fixed together.

FIG. 16 is a detail showing the connection between a second side plateand a top plate of FIG. 15.

DETAILED DESCRIPTION

The spindle drive which is shown in exploded views in FIGS. 1 to 3 hasan electric motor 1 whose motor shaft 2 is connected to a drive worm 20which meshes with a worm wheel 9 of a gear mechanism 3. The worm wheel 9is connected to a spindle nut 8 whose thread meshes with the thread of aspindle 7. Any rotation of the motor shaft 2 is transferred through thedrive worm 20 to the worm wheel 9 and thus to the spindle nut 8 which isconnected in one piece to the worm wheel 9 so that when the spindle 7 ismounted rotationally secured it changes its position in relation to themotor shaft 2 through the rotation of the spindle nut 8, i.e. is movedin the direction S1 or S2 in relation to the motor shaft 2 according toFIG. 2 depending on the direction of rotation of the electric motor 1.

The gear elements, drive worm 20, spindle 8 and worm wheel 9, arecombined into the gear mechanism 3 which has a gear housing 4 whichconsists of a housing shell 40 and a housing cover 41 which afterinserting the gear elements 8, 9, 20 into the housing shell 40 isconnected to the housing shell 40.

Two U-shaped bearing plates 5, 6 are fitted onto the ends of the spindle7 projecting out from the gear housing 4, wherein the side arms 52, 53and 62, 63 of these bearing plates are aligned opposite one another andtheir connecting arms 51, 61 which connect the side arms 52, 53 and 62,63 together have window-shaped through openings 55, 65 for receiving thespindle 7. The side arms 52, 53, and 62, 63 are thus designed so thatthey can engage in each other with slight play and thereby produce apositive connection which has a certain play. For this purpose the onebearing plate 5 has two side arms 52, 53 designed as tabs, while the oneside arm 62 of the other bearing plate 6 has a rectangular window-shapedopening 66 while the other side arm 63 is designed U or clip-like andhas a corresponding recess 67.

If the two bearing plates 5, 6 are inserted in each other then thetab-shaped side arms 52, 53 of the one bearing plate 5 substantiallyfill out the window shaped opening 66 or the recess 67 of the side arms62, 63 of the other bearing plate 6. For compensating tolerances eitherthe tab-shaped side arms 52, 53 of the one bearing plate 5 in thejoining direction of the bearing plates 5, 6 are either slightly shorterthan the length of the window-shaped opening 66 or recess 67 of the sidearms 62, 63 of the other bearing plate 6, or the tab-shaped side arm 52of the one bearing plate is longer than the window-shaped opening 66 ofthe side arm 62 on the other bearing plate 6 and in the connectingdirection of the bearing plates 5, 6 can be fitted through a cut outsection 68 in the connecting arm 61 of the other bearing plate 6 whichwidens out the window shaped opening 66 of the corresponding side arm 62of the other bearing plate 6 so that the tab shaped side arm 52 of thebearing plate 5 can project through the window shaped opening 66 andthus through the connecting arm 61 of the other bearing plate 6, or theframe of the side arm 62 surrounding the window shaped opening 66 overthe connecting arm 51 of the bearing plate 5, as can be seen from theillustration in FIG. 6. After connecting the bearing plates 5, 6 intothe bearing shell the fixing points 71, 72, 73 provided at the ends ofthe upper side arms 52, 62 of the bearing plates 5, 6 and projectingover the relevant connecting arms 51, 61 of the other bearing plate 5, 6are accessible for fixing the spindle or worm gearing on the one of thetwo relative movable parts.

In the region of the window-shaped spindle passages 55, 56 through thebearing plates 5, 6 the connecting arms 51, 61 have in relation to thegear housing 4 concave curvatures 54,64 which correspond to convexhousing sections 42, 43 of the gear housing 4, i.e. the housing shell 40and the housing cover 41. The curvatures 42, 43 of the gear housing 4and the curvatures 54, 64 of the connecting arms 51, 61 correspond witheach other so that the gear mechanism 3 can swivel inside the bearingshell formed from the bearing plates 5, 6 about an axis running parallelto the motor shaft 2 and thus can compensate pivotal movements of theparts which are movable relative to each other, of which one part isconnected through a fixing tab 70 to the spindle 7 and the other of thetwo relatively movable parts is connected through the fixing points 71,72, 73 to the bearing shell which is formed by the bearing plates 5, 6.

In order to assemble the spindle or worm drive the gear elements, namelythe worm wheel 9 and the spindle nut 8, after their connection with thespindle 7, they are inserted into the housing shell 40 of the gearhousing 4 and are connected to the worm 20 which is attached to themotor shaft 2. After fitting the housing cover 41 onto the housing shell40 and connecting it to the gear housing 4 the gear mechanism 3 iscomplete. The bearing plates 5, 6 are then pushed from both sides viathe window shaped through openings 55, 65 onto the spindle 7 and theside arms 52, 53; 62, 63 of the bearing plates 5, 6 are pushed into eachother and the concave and convex bearing shell sections 54, 64 of thebearing plates 5, 6 bear without play against the concave and convexhousing parts 42, 43 of the gear housing 4. Finally the abutting sideedges 521, 522, 661, 662; 531, 532, 671, 672 of the side arms 52, 62 and53, 63 of the bearing plates 5, 6 are connected together by means oflaser welding which run as welding contours 74, 75, 76 at least over apart of the length of the side edges 521, 522, 661, 662; 531, 532, 671,672.

In order to connect the spindle or worm drive to the adjusting drive theone end of the spindle 7 is connected to the fixing tab 70 which isfixed on the first of the two relatively movable parts while the bearingplates 5, 6 which are connected together to form the bearing shell areconnected to the second of the relatively movable parts.

In the assembled state of the gear mechanism 3 and the bearing shellformed from the bearing plates 5, 6 as illustrated in FIGS. 4 to 6, theside edges 521, 522 and 531, 532 of the tab-shaped side arms 52, 53 ofthe one bearing plate 5 are located adjoining the inner side edges 661,662 and 671, 672 of the window shaped opening 66 and recess 67respectively of the side arms 62, 63 of the other bearing plate 6. Ascan be seen from the perspective illustrations of the assembled driveaccording to FIG. 4 to 6, the ends of the tab-shaped side arm 52 of theone bearing plate 5 and of the end of the side arm 62 of the otherbearing plate 6 defining the window shaped opening 66 project over therelevant connecting arms 51, 61 of the relevant other bearing plate 5, 6and enable a corresponding match to the dimensions of the gear housing 4in the connecting region so that a play-free connection between the gearmechanism 3 and the bearing shell 5, 6 is guaranteed.

An embodiment for a drive according to the invention is shown in FIGS. 7to 16 where the bearing shell consists of four bearing plates.

In FIG. 7 a base plate 800 is shown which has two slit like openings810. A side plate 820 with a fixing tab 830 is pushed into one of thetwo slit like openings 810 of the base plate 800; this is shown indetail in FIG. 8. The side plate 820 furthermore has a further fixingtab 840 which is described further below in connection with the fixingof the side plate 820 on a top plate.

In the illustration according to FIG. 9 a second side plate 850 ispushed by its fixing tab 860 onto the base plate 800. It can be seen inFIG. 9 that the width of the slit like openings 810 is slightly largerthan the width of the associated fixing tabs 830 and 860 so that the twoside plates 820 and 850 have a slight clearance and thus are fixedeasily movable on the base plate 800.

FIGS. 10 and 11 show how the gear housing 4 already described in furtherdetail above in connection with FIGS. 1 to 6 is inserted with theelectric motor 1 into the arrangement which comprises the base plate 800and the two side plates 820 and 850. FIG. 10 thereby shows a view frominclined left and FIG. 11 shows a view from inclined right.

Furthermore it can be seen in FIGS. 10 and 11 that each of the two sideplates 820 and 850 each has a through opening 870 and 880. Left andright of the through openings 870 and 880—thus on both sides of thethrough openings 870 and 880—each of the two side plates 820 and 850each has two concave and convex bearing shell sections 890, 900, 910 and920. The through openings 870 and 880 serve for passing through thespindle 7 which is shown in further detail for example in FIG. 1 andwhich is described above in connection with FIG. 1.

In FIG. 12 a top plate 930 is shown which has a recess 940 along theedge. The edge recess 940 serves—as described in detail further down inconnection with FIGS. 13 to 16—to receive the further fixing tab 840 ofthe one side plate 820.

FIGS. 13 and 14 show the finished assembled drive after the gear housing4 has been inserted between the two side plates 820 and 850. Inparticular it can be seen easily from FIG. 13 how the concave and convexbearing shell sections 890, 900, 910 and 920 bear 30 without clearanceagainst the gear housing 4 which has a concave shape in the fixing area.In FIG. 13 it can further be seen how the top plate 930 is fixed on thetwo side plates 820 and 850. Also seen is the further fixing tab 840 ofthe one side plate 820 which engages in the recess 940 along the edge ofthe top plate 930. On the side 950 of the top plate 930 opposite theedge recess 940 the top plate 930 rests on the second side plate 850.

FIG. 14 shows the assembled drive from the back. It is possible to seethe electric motor 1 and the base plate 800 as well as the slit likeopenings 810 into which the fixing tab 830 of the one side plate 820 aswell as the fixing tab 860 of the second side plate 850 engage.Furthermore it is possible to see how the further fixing tab 840 of theone side plate 820 engages in the edge recess 940 of the top plate 930.

FIGS. 15 and 16 show in detail how the four bearing plates 800, 820, 850and 930 are connected and fixed together after the gear housing 4 hasbeen inserted into the bearing shell 960 which is formed by thesebearing plates. In the connecting regions between the bearing plates800, 820, 850 and 930 there are grooved zones or grooves which carry thereference numerals 970, 980, 990 and 1000 in FIG. 15. The four bearingplates are thereby welded together in these grooved zones 970, 980, 990and 1000, thus through “grooved seam welding”. Grooved seam welding hasthe advantage over welding along the butt joints between adjoiningconnecting parts that no full penetrating welding passes through theseam point.

FIG. 15 also contains arrows 1010, 1020, 1030 and 1040 which are torepresent the welding direction of a welding laser beam. It can be seenthat the welding direction of the laser beam stands at an angle of about45° to the bearing plates which are to be connected together. Aparticularly solid welding seam is formed by an angle of about 45°. Thewelding seams thus formed carry the reference numerals 1050, 1060, 1070and 1080 in FIG. 15.

In FIG. 16 the connection between the second side plate 850 and the topplate 930 is shown once more in detail. The groove 980 is shown intowhich the laser beam 1090 is directed. The laser beam 1090 thereby hasan angle of about 45° to the second side plate 850 as well as an angleof about 45° to the top plate. “Full penetrating welding” can thus notoccur.

1. A spindle or worm drive for adjustment devices in motor vehicles,with at least one of a fixed spindle and a fixed toothed rack which isfixed on a first of two parts which can be moved relative to a second ofthe two parts, with a gear mechanism which is connected to the second ofthe relatively movable parts, and with a gear housing for receiving thegear mechanism, wherein the gear housing is enclosed free from backlashand able to pivot about at least one axis by a bearing shell, andwherein the gear housing has at least one of a concave and convexhousing part which is surrounded by at least one of a convex and concavebearing shell section, wherein the bearing shell section is formed fromat least two bearing plates which each bear and are fixed free frombacklash against the gear housing and surround the gear housing, whereinthe at least two bearing plates of the bearing shell section comprisetwo interfitting bearing plates which after inserting the gear housingare connected together and fixed on the second of the relatively movableparts, and wherein the bearing plates are fitted in each other in thedirection of the longitudinal extension of one of the spindle andtoothed rack and have through openings for passing therethrough one ofthe spindle and toothed rack.
 2. The spindle or worm drive according toclaim 1, wherein the gear housing is made from plastics and the bearingshell is made from a material which is suitable to take up crash forces.3. The spindle or worm drive according to claim 1, wherein the bearingplates are U-shaped and have side arms that engage in each other andhave connecting arms which connect the side arms together and havethrough openings for passing therethrough one of the spindle and toothedrack, and have concave and convex curvatures.
 4. The spindle or wormdrive according to claim 3, wherein the concave and convex bearing shellsections are arranged on both sides of the through openings for passingtherethrough one of the spindle and toothed rack.
 5. The spindle or wormdrive according to claim 3, wherein the side arms of one bearing plateare designed as tabs which engage in the one side arm provided with awindow shaped opening and in the other side arm of the other bearingplate provided with a U-shaped recess.
 6. The spindle or worm driveaccording to claim 5, wherein the tab shaped side arm of the one bearingplate in the connecting direction of the bearing plates is shorter thanthe U-shaped recess of the side arm of the other bearing plate and thetab-shaped side arm of the one bearing plate in the connecting directionof the bearing plates can be pushed through a cut-out section in theconnecting arm of the other bearing plate which widens out the windowshaped opening of the corresponding side arm of the other bearing plate.7. The spindle or worm drive according to claim 6, wherein the tabshaped side arm of the one bearing plate in the connecting direction ofthe bearing plates is longer than the window shaped opening and theframe surrounding the window shaped opening is longer than thetab-shaped side arm so that at the front ends of the tab shaped side armof the one bearing plate in the connecting direction of the bearingplates and on the frame surrounding the window shaped opening there arefreely accessible fixing points.
 8. The spindle or worm drive accordingto claim 6, wherein the side arms of the bearing plates in the assembledstate of the adjusting device are positively connected together.
 9. Thespindle or worm drive according to one of claims 1 to 2, wherein thebearing shell has a base plate, two side plates and a top plate, wherebythe base plate and the top plate are arranged substantially parallel toeach other and are connected together through the side plates which arearranged substantially parallel to each other.
 10. The spindle or wormdrive according to claim 9, wherein the base plate has two slit likeopenings of which one opening serves to receive a fixing tab of one ofthe two side plates and of which the other opening serves to receive afixing tab of the other of the two side plates.
 11. The spindle or wormdrive according to claim 10, wherein the one side plate has a furtherfixing tab which is mounted on a side of the side plate opposite the onefixing tab and engages in a recess in the edge of the top plate.
 12. Thespindle or worm drive according to claim 9, wherein the side plates havein the direction of the longitudinal extension of one of the spindle andtoothed rack full length openings for passing therethrough one of thespindle and toothed rack.
 13. The spindle or worm drive according toclaim 9, wherein the side plates have one of concave and convex bearingshell sections.
 14. The spindle or worm drive according to claim 13,wherein one of the concave and convex bearing shell sections arearranged on both sides of the full-length openings for passingtherethrough one of the spindle and toothed rack.
 15. The spindle orworm drive according to claim 9, wherein the base plate, the two sideplates and the top plate are welded for fixing.
 16. The spindle or wormdrive according to claim 15, wherein the plates are laser-welded. 17.The spindle or worm drive according to claim 16, wherein the weldedseams lie in grooves which are formed at the connecting regions betweenplates standing on each other.
 18. The spindle or worm drive accordingto claim 9, wherein the side arms of the bearing plates are connectedtogether through welding contours.
 19. The spindle or worm driveaccording to claim 1, wherein the bearing shell is made from a metalmaterial which is suitable to take up crash forces.
 20. A method formanufacturing a spindle or worm drive for adjustment devices in motorvehicles, with at least one of a fixed spindle and a fixed toothed rackwhich is fixed on a first of two parts which can be moved relative to asecond of the two parts, with a gear mechanism which is connected to thesecond of the relatively movable parts, and with a gear housing forreceiving the gear mechanism, wherein the gear housing is enclosed freefrom backlash and able to pivot about at least one axis by a bearingshell, wherein gear elements after their connection with one of thespindle and toothed rack are inserted into a housing shell of the gearhousing and are connected to a drive element of a motor shaft, wherein agear cover is connected to the housing shell of the gear housing toclose up the gear mechanism, wherein the finished made gear housing isenclosed free from backlash by the bearing shell, wherein as gearhousing is used a housing having at least one of a concave and convexhousing part, and the bearing shell has at least a convex and concavebearing shell section, and wherein the gear housing is surrounded by thebearing shell in that at least two bearing plates of the bearing shellare adjusted and fixed without play relative to the gear housing, andwherein the bearing plates are pushed from both sides throughwindow-shaped through openings onto the spindle, side arms of thebearing plates are pushed into each other until the concave and convexbearing shell sections of the bearing plates bear free from backlashagainst the concave and convex housing parts of the gear housing, andwherein abutting side edges of the side arms of the bearing plates areconnected together by laser welding at least over a part of theirlength.
 21. The method according to claim 20, wherein one end of thespindle is connected to a connecting tab which is fixed on the first ofthe two relatively movable parts, and the bearing plates which areconnected together are connected to the second of the relatively movableparts.
 22. The method according to claim 21, wherein the bearing shellis formed from four bearing plates in which two side plates are pushedonto a base plate, the gear housing is inserted between the two sideplates, and a top plate is fitted onto the two side plates and the fourbearing plates are aligned relative to each other free from backlash andfixed together.
 23. The method according to claim 22, wherein the twoside plates are pushed from both sides through window shaped full-lengthopenings onto the spindle and aligned until the concave and convexbearing shell sections of the side plates bear free from backlashagainst the concave and convex housing parts of the gear housing. 24.The method according to claim 23, wherein the four bearing plates arefixed together by laser welding.
 25. The method according to claim 24,wherein the laser welding is carried out in groove zones which areformed in the connecting region of the bearing plates which stand oneach other.
 26. The method according to claim 25, wherein the laserwelding is carried out at an angle of about 45° to the bearing plateswhich are to be connected.
 27. The method according to claim 23, whereinthe four bearing plates are fixed together by welding.
 28. A spindle orworm drive for adjustment devices in motor vehicles, with at least oneof a fixed spindle and a fixed toothed rack which is fixed on a first oftwo parts which can be moved relative to a second of the two pads, witha gear mechanism which is connected to the second of the relativelymovable parts, and with a gear housing for receiving the gear mechanism,wherein the gear housing is enclosed free from backlash and able topivot about at least one axis by a bearing shell, and wherein the gearhousing has at least one of a concave and convex housing part which issurrounded by at least one of a convex and concave bearing shellsection, wherein the bearing shell section is formed from at least twobearing plates which each bear and are fixed free from backlash againstthe gear housing and surround the gear housing, and wherein the at leasttwo bearing plates of the bearing shell section comprise a base plate,two side plates and a top plate, whereby the base plate and the topplate are arranged substantially parallel to each other and areconnected together through the side plates which are arrangedsubstantially parallel to each other.